[Edit:] Updated with a newer, more finished version.
The Lost Seas is more or less considered a mythical realm that exists between the Mortal World and the Divide. It consists of several lush tropical islands and is host to much volcanic activity. According to seafaring stories, the Lost Seas is home to the Maaré; a race of magical beings who were first created by the goddess Demetriel, purposed to be part of her personal army during the War of Eternity. Other races that reside here are the Seshani snakebloods, who are half-breeds of humans and snakes created by the witch Illadria, and the Skerr lizardfolk, who are the first, failed creation of Demetriel. The only way in and out of the mystical mists that surround the Lost Seas is the Mistway Gate; of which is often used to send raiding parties to the Mortal World, who then proceed to attack merchant vessels and abduct the crew. Upon their return to the Lost Seas, these abducted mortals are thrown into slavery or forced to fight as gladiators in the grand arena of the city of Nazjar.
Brushes by StarRaven - [link]
More about Third Era - [link]